Patient controlled power operated kit for hospital bed



April 1967 J. L. PETERSON 3,311,933

PATIENT CONTROLLED POWER OPERATED KIT FOR HOSPITAL BED Filed Aug. 12, 1965 F77. ERA 5Y6 United, States Patent Ofitice A 3,311,933 PATIENT CONTROLLED POWER OPERATED KIT FOR HOSPITAL BED James L. Peterson, 1150 1st St, Idaho Falls, Idaho 83401 Filed Aug. 12, 1965, Ser. No. 479,202 1 Claim. (Cl. -66) This invention relates to an improved power operated device for raising or lowering the back or foot portion of a hospital bed,,1'aising or lowering the entire bed or tilting the bed.

More particularly the invention relates to a device in which the pressure creating hydraulic pump is continuously run in one direction although the high pressure hydraulic fluid is alternately fed to one side or the other of hydraulic motors.

The invention will be more fully understood with reference to the attached drawings which illustrate one embodiment of my invention and in which like reference numerals refer to like parts in the various drawings.

FIGURE 1. is a side elevation of a hospital bed with my hydraulic unit attached thereto.

FIGURE 2 is a partially schematic view of the hydraulic and electrical components of my invention.

FIGURE 3 is a detail view of the electrical actuating mechanism for one of the valves in my hydraulic device, and

FIGURE 4 is a partial cross-section of the internal mechanism of the foot portion of the hospital bed.

A hospital bed incorporating my invention has a conventional bed frame 1 and mattress frame 4. To it are attached a special upper leg 2 and lower leg 3. My hydraulic device is contained in a housing 5 which is preferably suspended from the bed frame 1 by springs 6.

The patient operates the hydraulic unit through a control unit 7 in which are four double throw switches 8 and a pilot light 24 which glows continuously to show that the unit has been plugged into the wall.

The various raising and lowering operations are performed by four hydraulic motors. They are the head hydraulic gear motor 9, the foot hydraulic gear motor 10, the back hydraulic piston motor 11, and the leg hydraulic piston motor 12.

Contained in the housing 5 are the four special valves which control these motors. They are the head motor valve 13, the foot motor valve 14, the back motor valve 15, and the leg motor valve 16.

Within the control unit 7 are the four switches which control these valves. As shown in FIGURE 2 they are the headvalve switch 17, the foot valve switch 18, the back valve switch 19, and the leg valve switch 20.

An electric plug 21 is connected to a conventional power supply thus grounding electric wire 22 and charging electric Wire 23 which is connected to each of the switches in the control unit 7 as well as the pilot light 24.

Each of the switches has two operative positions as well as the inoperative position in which each is shown in FIG- URE 2.

All four switches 17, 18, 19 and energize the electric motor circuit wire 25 when they are put in the raised operative position. Additionally, switches 17 and 18 energize the circuit 25 when they are put in the lowered position. This circuit operates the electric motor 26 which in turn runs the hydraulic pump 27. This hydraulic pump connects the low pressure hydraulic reservoir 28 and the high pressure hydraulic reservoir 29, creating pressure in the high pressure reservoir when the pump and motor are operated.

The electrical control mechanism for each of the valves is identical. It comprises two solenoids which are alter- 3,31 1,933 Patented Apr. 4, 1967 nately activated. FIGURE 3 shows one of these valves, the back motor valve 15. As can be seen in FIGURE 2, all four of these valves operate by rotating an internal core member. This core member in FIGURE 3 is controlled by the armature-handle 30. The armature-handle 30 is normally biased in the inoperative position by springs 31 and 32.

When the back valve switch 19 is put in the upward position it raises the back of the bed. It does this by energizing electric line 33 which in turn energizes solenoid 34. Solenoid 34 thus attracts the armature-handle 30 and causes the core member of back motor valve 15 to rotate counterclockwise.

This counterclockwise rotation causes the high pressure hydraulic reservoir 29 to .be connected to hydraulic line 35 which feeds into the cylinder of the back hydraulic piston motor 11 forcing out the piston and connecting rod 36. This raises the back section of the bed 37 pivoting it around joint 38. Also shown is spill-over line 39 which connects the upper end of the cylinder with the low pres sure reservoir. This both alloys air to escape and recap tures any hydraulic fluid which passes the piston.

The back of the bed is lowered by depressing the back valve switch 19 into the lower operable position. This energizes electric line 40 but does not energize the motor circuit 25. Electric line 49 in turn activates the solenoid 41 which attracts the armature-handle 30. This causes the core of valve 15 to rotate in a clockwise direction connecting hydraulic line 35 with line 42.

The weight of the patient on the back section 37 as well as the weight of the mechanism itself forces the fluid out of the cylinder of the back hydraulic piston motor 11 and through line 42 into the low pressure reservoir 28. When switch 17 is moved to the inoperative position, de-energizing solenoid 41, the tension on spring 31 returns the armature-handle 30 and the core of valve 15 to the inoperative position shown in FIGURE 2.

In a similar manner the leg valve switch 20 operates the leg motor valve 16 and the leg hydraulic piston motor 12 to both raise and lower the leg portion of the mattress frame 4.

When head valve switch 17 is put in the upward position it activates both electric line 43 and the motor circuit line 25. Line 43 energizes solenoid 44 causing the core of the head motor valve 13 to rotate clockwise. This connects the high pressure hydraulic reservoir 29 with the hydraulic line 45 and further connects the hydraulic line 47 with the sump line 48.

Lines 45 and 47 lead to the two ports of the foot hydraulic gear motor 9. When the high pressure hydraulic reservoir is connected to line 45 it causes the main gear 46, which is intermeshed with the idler gear, to rotate in a counterclockwise direction. Gear 46 is connected to red 49 which similarly rotates along with machine screw 58. The screw cooperates with the internal threading of the upper leg 2, thus raising the upper leg as screw and rod 49 rotate.

When the head valve switch 17 is in the lower position solenoid 51 is activated which causes the core of valve 13 to rotate in a counterclockwise direction. This connects the high pressure hydraulic reservoir 29 with hydraulic line 47 and further connects the hydraulic line 45 with the sump line 48. In this position the main gear 46 of the motor 9 rotates in a clockwise direction causing rod 49 and screw 50 to revolve in the opposite direction lowering the leg and frame.

The foot valve switch 18 operates in an identical man ner, raising the foot of the bed when the switch is in the upper operable position and lowering the foot of the bed when the switch is in the lower operable position.

When switches 17 and 18 are operated together the entire bed raises or lowers itself; when only one switch is operated the bed will tilt itself.

Having described by invention I claim:

A patient operated power unit for attachment to hospital beds and capable of selectively raising and lowering the back and leg portions of the mattress frame and also raising, lowering, and tilting the entire bed frame comprising:

(a) a low pressure hydraulic reservoir for storage of hydraulic fluid;

(b) a high pressure hydraulic reservoir for storing said fiuid under pressure;

(c) a hydraulic pump connecting said low and high pressure reservoir for maintaining said fluid under pressure and said high pressure reservoir;

(d) an electric motor for operating said hydraulic (e) hydraulic motors for carrying out the above several operations wherein said hydraulic motors for raising and lowering the mattress frame each comprise a main and idler gear meshed together in a unitary housing with hydraulic ports on either side and a valve having inoperative position and two operative positions; the first operable position connecting the high pressure reservoirs and the first port 20 and further connecting the low pressure reservoir and the second port whereby the main gear in the hy- .t' draulic motor revolves in one direction and the second operative position of said valves connecting said reservoirs to the opposite ports whereby the main gear in said hydraulic motors revolves in the opposite direction;

(f) electrically operated valves for selectively connecting through hydraulic lines saidhydraulic 'motors' and said hydraulic reservoirs; and l i (g) manually operable electrical switches for engaging said electric motor and simultaneously opening preselected valves to perform the desired operation, whereby said electric motor and high pressure pump runs only in a single direction during all of the above operations.

References Cited by the Examiner UNITED STATES PATENTS 2,217,783 10/1940 Bell 5 66 X 2,520,455 8/1950 Clachko 5-66 X 2,702,508 2/1955 Peterson 5-66 X 2,831,200 4/1958 Olsen 5- -69 3,191,195 6/1965 Schlackman et a1. 5-65 FRANK B. SHERRY, Primaly Examiner. CASMIR A. NUNBERG, FRANCIS K. ZUGEL,

Examiners. 

